Computer network connects two or more autonomous computers. The computers can be geographically located anywhere.

1. INTRODUCTION TO
COMPUTER NETWORKS
Presented by: Haider Ali Malik
University of Sargodha

2. INTRODUCTION TO COMPUTER
NETWORKS
Introduction to Computer Networks

3. Computer Networks
Computer network connects
two or more autonomous
computers.
The computers can be
geographically located
anywhere.
Introduction to Computer Networks

4. LAN, MAN & WAN
Network in small geographical Area (Room, Building or a
Campus) is called LAN (Local Area Network)
Network in a City is called MAN (Metropolitan Area
Network)
Network spread geographically (Country or across Globe) is
called WAN (Wide Area Network)
Introduction to Computer Networks

5. Applications of Networks
Resource
Sharing
• Hardware
(computing
resources,
disks,
printers)
• Software
(applicatio
n software)
Informati
on
Sharing
• Easy
accessibilit
y from
anywhere
(files,
databases)
• Search
Capability
(WWW)
Communi
cation
• Email
• Message
broadcast
Remote
computing
Distributed
processing
(GRID
Computing)
Introduction to Computer Networks

6. Network Topology
The network topology
defines the way in
which computers,
printers, and other
devices are connected. A
network topology
describes the layout of
the wire and devices as
well as the paths used
by data transmissions.
Introduction to Computer Networks

7. Bus Topology
Commonly referred to
as a linear bus, all the
devices on a bus
topology are
connected by one
single cable.
Introduction to Computer Networks

8. Star & Tree Topology
The star topology is the most
commonly used architecture in
Ethernet LANs.
When installed, the star topology
resembles spokes in a bicycle wheel.
Larger networks use the extended star
topology also called tree topology.
When used with network devices that
filter frames or packets, like bridges,
switches, and routers, this topology
significantly reduces the traffic on the
wires by sending packets only to the
wires of the destination host.
Introduction to Computer Networks

9. Ring Topology
A frame travels around the
ring, stopping at each
node. If a node wants to
transmit data, it adds the
data as well as the
destination address to the
frame.
The frame then continues
around the ring until it
finds the destination node,
which takes the data out
of the frame.
Single ring – All the
devices on the
network share a
single cable
Dual ring – The dual
ring topology allows
data to be sent in
both directions.
Introduction to Computer Networks

10. Mesh Topology
The mesh topology
connects all devices
(nodes) to each other for
redundancy and fault
tolerance.
It is used in WANs to
interconnect LANs and for
mission critical networks
like those used by banks
and financial institutions.
Implementing the mesh
topology is expensive and
difficult.
Introduction to Computer Networks

11. Network Components
Physical Media
Interconnecting Devices
Computers
Networking Software
Applications
Introduction to Computer Networks

12. Networking Media
Networking media can
be defined simply as the
means by which signals
(data) are sent from one
computer to another
(either by cable or
wireless means).
Introduction to Computer Networks

13. Networking Devices
HUB
Switches
Routers
Wireless
Access
Points
Modems
etc.
Introduction to Computer Networks

14. Computers: Clients and Servers
In a client/server network
arrangement, network
services are located in a
dedicated computer whose
only function is to respond
to the requests of clients.
The server contains the
file, print, application,
security, and other services
in a central computer that
is continuously available to
respond to client requests.
Introduction to Computer Networks

15. Networking Protocol: TCP/IP
Introduction to Computer Networks

16. Applications
Searchable Data (Web Sites)
E-Commerce
News Groups
Internet Telephony (VoIP)
Video Conferencing
Chat Groups
Instant Messengers
Internet Radio
E-mail
Introduction to Computer Networks